Dr. Yu-Chi Weng is assistant professor of the Laboratory of Sound Material-Cycle Systems Planning, Division of Environmental Engineering, Faculty of Engineering, Hokkaido University since April, 2011. He received his Dr. Eng. degree from Kyoto University (2009), and got his bachelor (1999) and master (2001) degrees from National Cheng Kung University. Before joining Hokkaido University, he was as a specially appointed assistant professor at Okayama University (April 2009- March 2011), and an assistant research fellow at the Taiwan Institute of Economic Research, involving in environmental cost-benefit analysis studies. Now he focuses his study on environmental systems analysis and applied econometrics, with particularly emphases on the development of sound material-cycle society and sustainable lifestyle.